From: Lars Ingebrigtsen <larsi@gnus.org>
To: Paul Eggert <eggert@cs.ucla.edu>
Cc: Andy Moreton <andrewjmoreton@gmail.com>, emacs-devel@gnu.org
Subject: Re: encode-time vs decode-time
Date: Wed, 31 Jul 2019 21:03:07 +0200 [thread overview]
Message-ID: <87v9viuivo.fsf@mouse.gnus.org> (raw)
In-Reply-To: <502b23f8-58ed-38ff-ae50-fae391129a10@cs.ucla.edu> (Paul Eggert's message of "Tue, 30 Jul 2019 12:54:21 -0500")
Paul Eggert <eggert@cs.ucla.edu> writes:
>> this is very confusing indeed
> To some extent the confusion is inherent: there are a lot of useful
> ways to represent and manipulate times, and people unfamiliar with the
> issues will find this complexity confusing. That being said, it would
> be good to simplify the Emacs API for time without significantly
> hurting functionality or compatibility.
>
> So, how about this idea. First we go along the lines of your
> suggestion, and change decode-time to return a ninth slot with a
> numerator-denominator pair that preserves all the precision of its
> argument. Second, we change (encode-time TIME t) so that it also
> preserves all the precision of its argument. This will cause
> (encode-time (decode-time TIME) t) to return a value equivalent to
> TIME, which will simplify roundtripping.
I think this sounds workable, but I think it would be even better to
introduce some new functions instead of overloading our poor encode-time
function.
When you did the major sanitation in this area last year (which was
overall a very good thing), you did stuff like
- (now (string-to-number (format-time-string "%s")))
+ (now (encode-time nil 'integer))
and
- (now (float-time))
+ (now (encode-time nil 'integer))
and many similar transforms. The new code is definitely better than the
old code, and it's not more cryptic than it used to be, really.
However, I think it would have been even better to introduce a new
function to enable people who are unfamiliar with how this all works to
just read the code and understand what it's doing.
So I think the things up above there should really be calls to a new
function `get-current-time', that returns the same thing as
`(encode-time nil 'integer)'. It should default to `integer', but can
have an optional argument that says what form of "internal second time
format" to return (i.e., `list', `t').
And then, finally, I think there should be a function to convert between
these "internal second time" formats. Like... `convert-time-format',
which would be like `(encode-time time 'list)' (etc).
And then leave encode-time/decode-time a simple pair that would do
nothing but convert between "internal second time format" and "decoded
time format".
--
(domestic pets only, the antidote for overdose, milk.)
bloggy blog: http://lars.ingebrigtsen.no
next prev parent reply other threads:[~2019-07-31 19:03 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-29 9:48 Support for sub-second time in decoded time Lars Ingebrigtsen
2019-07-29 14:03 ` Stefan Monnier
2019-07-29 14:12 ` Lars Ingebrigtsen
2019-07-29 14:43 ` Stefan Monnier
2019-07-29 15:00 ` Lars Ingebrigtsen
2019-07-29 17:50 ` Stefan Monnier
2019-07-30 11:33 ` Lars Ingebrigtsen
2019-07-29 16:08 ` encode-time vs decode-time Stefan Monnier
2019-07-30 10:32 ` Lars Ingebrigtsen
2019-07-30 11:34 ` Andy Moreton
2019-07-30 11:37 ` Lars Ingebrigtsen
2019-07-30 17:54 ` Paul Eggert
2019-07-30 22:50 ` Paul Eggert
2019-07-31 19:03 ` Lars Ingebrigtsen [this message]
2019-07-31 19:31 ` Stefan Monnier
2019-08-06 1:48 ` Paul Eggert
2019-08-06 14:21 ` Eli Zaretskii
2019-08-06 15:59 ` Paul Eggert
2019-08-06 18:23 ` Eli Zaretskii
2019-08-07 1:02 ` Paul Eggert
2019-08-07 2:41 ` Stefan Monnier
2019-08-07 14:47 ` Eli Zaretskii
2019-08-11 23:39 ` Lars Ingebrigtsen
2019-08-17 6:47 ` Paul Eggert
2019-08-07 11:33 ` Lars Ingebrigtsen
2019-08-17 7:54 ` Paul Eggert
2019-08-17 8:16 ` Eli Zaretskii
2019-08-17 9:33 ` Paul Eggert
2019-08-17 20:46 ` Lars Ingebrigtsen
2019-08-17 20:56 ` Paul Eggert
2019-08-17 21:42 ` Stefan Monnier
2019-08-17 22:53 ` Paul Eggert
2019-08-19 21:12 ` Stefan Monnier
2019-08-21 10:55 ` Adam Porter
2019-08-21 20:20 ` Paul Eggert
2019-08-26 10:59 ` Adam Porter
2019-08-26 21:35 ` Paul Eggert
2019-08-07 14:44 ` Eli Zaretskii
2019-08-07 11:41 ` Lars Ingebrigtsen
2019-08-17 9:25 ` Paul Eggert
2019-08-17 20:51 ` Lars Ingebrigtsen
2019-07-29 14:23 ` Support for sub-second time in decoded time Eli Zaretskii
2019-07-29 14:59 ` Lars Ingebrigtsen
2019-07-29 16:46 ` Paul Eggert
2019-07-30 11:43 ` Lars Ingebrigtsen
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